Isolation structure with multiple components to increase image sensor performance

Abstract

Various embodiments of the present disclosure are directed towards an image sensor including a plurality of photodetectors disposed within a substrate. The photodetectors are disposed respectively within a plurality of pixel regions. A floating diffusion node is disposed along a front-side surface of the substrate at a middle region of the plurality of pixel regions. A plurality of well regions is disposed within the substrate at corners of the plurality of pixel regions. An isolation structure extends into a back-side surface of the substrate. The isolation structure comprises a plurality of elongated isolation components disposed between adjacent pixel regions, a middle isolation component aligned with the floating diffusion node, and multiple peripheral isolation components aligned with the plurality of well regions. The elongated isolation components have a first height and the middle and peripheral isolation components have a second height less than the first height.